This is a difficult problem in that it dosen't have enough information for a reliable solution. For example, 500 units of Ore yields 321 units of X, 128 units of Y, and 321 units of Z. Its yields more units than it put in, 321+321+128 . Ok, Lets assume that the units for X,Y,Z are different units. This is a problem because we need to know the conversion between units if different units are being used, otherwise any analysis is useless.